Originally Posted by
Machka
When he wears those wool socks, just make sure his shoes are not too tight. If his shoes are tight with all that sock in there, his feet will be cold, but if his shoes are a bit on the looser side (he should be able to wiggle his toes) his feet will be warmer.
And if the shoes have venting in them, you can cover that with duct tape ... lots of cyclists do that. It's the inexpensive bootie ... and custom-built!

Machka's advice is always good & helpful. She has given me advice more then once on other web sites that has helped.
That said & I hope Machka doesn't mind me stating something that I know works for covering vented shoes, here is what also works. Instead of duct tape, which could leave a sticky residue that may be hard to clean off of the shoe you can also try those shoe booties that are used in surgery rooms. They have elastic to keep them on the shoes. You may have to cut a small hole in the bottom if you have clipless pedals for the cleat. Another thing that also works is plastic bread bags. The best way to use those is inside the shoe.